38 results about "Peptide mass" patented technology

The present invention relates to a method for phosphorylation site-specific labeling of phosphoproteome with a site-specific tagging reagent and analyzing of the resulting labeled one, more especially, a method for in-situ tagging of phosphorylation sites of phosphoproteins retained in polymeric gel with a nucleophilic tagging reagent. It also relates a method for generating new proteolytic cleavable sites at formerly phosphorylation sites by a proper choice of a nucleophilic tagging reagent. It also relates to a method for phosphopeptides analysis and phosphorylation site identification by in-gel digestion of the previously in-gel tagged proteins and subsequent mass analysis of the resulting peptides. The invention provides in-gel chemical tagging method for phosphoaminoacid residue of phosphoproteins retained in polymeric gel matrix. Phosphoprotein can be immobilized into gel matrix by a variety of methods such as gel electrophoresis. The immobilized phosphoproteins are retained in gel matrix during tagging reaction to phosphorylated aminoacid residue of phosphoproteins, and the resulting tagged proteins are also retained in gel matrix till following purification steps like washing of the tagging reagents are accomplished. The tagged proteins is digested by protease, and the resulting digested peptides is released from gel into solution and applied for peptide mass analysis.

The invention relates to a mass spectrometry calibration system that may be performed in real-time using the information contained within a sample without the addition of specific calibrants. When applied to a sample, such as a proteomic sample, the calibration system may identify the exact masses of peptides in the sample. The system involves the use of mathematical algorithms that iteratively estimate the error in the measurement and update the calibration parameters accordingly; thereby resulting in peptide mass identification.

A method for acquiring and analyzing polypeptide mass spectra comprising: creating first and second sets of fragmented ions using first and second fragmentation techniques; obtaining mass spectra of the first and second sets of fragmented ions; searching a database of fragments of a first fragment pair type and of a second fragment pair type to respectively provide a set of M ranked and a set of N ranked best matching polypeptide sequences; subtracting synthetic spectra corresponding to each of the M and N ranked sequences from the mass spectra to provide first and second sets of modified mass spectra; searching the database of fragments of the second fragment pair type and of the first fragment pair type to provide third and fourth sets of polypeptide sequences providing best matches to the first and second sets of modified spectra, respectively; and creating a cumulative ranking of the third and fourth sets.

The invention relates to a reagent for cutting peptides, in particular to a reagent for cutting sulfydryl-containing peptides from resins. In addition, the invention also relates to a method for cutting sulfydryl-containing polypeptides from resins, which is suitable for industrial production of sulfydryl-containing polypeptides. The reagent for cutting sulfydryl-containing polypeptides from resins comprises the following components in parts by weight: 85-95 parts of trifluoroacetic acid, 1-5 parts of triisopropylsilane, 1-4 parts of mercaptoundecanoic acid, 1-4 parts of phenol and 1-2 parts of water. The invention has the advantages that because ethanedithiol is a chemical reagent which is not produced at home, the cost of the ethanedithiol is expensive, and the ethanedithiol has effluvial smell in the reaction process; in the invention, mercaptopropionic acid is used for replacing the conventional ethanedithiol, thus the production cost can be lowered, the environment pollution is greatly reduced, and simultaneously, the effect of the peptide cutting reaction can also be improved; and meanwhile, the invention has the characteristics of low procurement cost, reduction of the three wastes, good crude peptide quality and the like, and is very suitable for industrial production of sulfydryl-containing polypeptides.

The present invention provides a preparation, which relates to the field of medicine, that is, the new pharmaceutical composition has bactericidal, especially, antibacterial and antiviral effects. A preparation of the present invention, containing blowfly antiviral peptide similar drug peptide H 2 N‑His‑Gly‑Val‑Ser‑Gly‑His‑Gly‑Gln‑His‑Gly‑Val‑His‑Gly‑COOH– and peptide HN 2 -(CH 2 ) 10 ‑CO‑Ile‑Leu‑Pro‑D‑Phe‑Lys‑D‑Phe‑Pro‑D‑Phe‑D‑Phe‑Pro‑D‑Phe‑Arg‑Arg‑NH 2 The mass ratio is 1:2 to 2:1 and auxiliary materials. In summary, the preparation has comprehensive antibacterial and antiviral effects, and the preparation (injection, gel, ointment, spray, etc.) can be used to treat herpes virus infection, vaginal herpes infection, HPV virus infection, and bacterial infection.

A method for preparing antioxidant peptides by using Bacillus subtilis to ferment rice dregs, the method is to first prepare Bacillus subtilis seed culture solution, then insert it into a fermentation medium, and carry out shaking table fermentation culture to obtain a fermentation solution; Enzyme, cooled to room temperature, centrifuged to remove bacteria and unfermented rice dregs, filtered the obtained fermentation supernatant, concentrated the filtrate, and freeze-dried. The invention uses rice dregs as raw materials to prepare antioxidant peptides, which has wide sources and low price, not only reduces the production cost of preparing antioxidant peptides, but also effectively comprehensively utilizes the by-product rice dregs, increases the added value of rice dregs, and expands its application range. Realize the large-scale industrial production of rice dregs antioxidant peptides. The product rice dregs protein antioxidant peptide prepared by the method of the invention has good quality, high antioxidant activity and strong reducing ability.

The invention relates to a method for extracting characteristic parameters of peptide mass spectrum peaks. The existing method has the disadvantage that it is difficult to ensure the accuracy of the extracted mass spectrum peak characteristic parameters when there is a large deviation in the distribution of the various points that form the peak in the peptide mass spectrum. The present invention proposes a method for extracting characteristic parameters of peptide mass spectrum peaks based on a nonlinear fitting method, using multiple sample point data, guided by the minimum difference between the actual data and the fitting result, and adopting an iterative method to continuously update the estimated value of the characteristic parameters, Until the convergence condition is satisfied, the final characteristic parameter estimation is obtained. This method can effectively reduce the adverse effects of the sample point distribution deviation on the solution of the characteristic parameters of the Gaussian curve, improve the numerical accuracy of the characteristic parameters, and then help improve the accuracy of peptide identification.

The invention provides a crosslinking dipeptide rapid identification method, comprising: 1) extracting effective spectrum peaks in a to-be-identified series-connected spectrogram, according to mass corresponding to each effective spectrum peak, searching a fragment index, to obtain a corresponding peptide fragment sequence as a candidate [alpha] peptide sequence, wherein the fragment index records mass of each fragment and the peptide fragment sequence corresponding to the mass of each fragment; 2) for each candidate [alpha] peptide sequence, according to parent ion mass of the to-be-identified series-connected spectrogram, calculating corresponding [beta] peptide mass, to obtain a corresponding candidate [beta] peptide sequence, combining the candidate [alpha] peptide sequence with the corresponding candidate [beta] peptide sequence, to obtain candidate crosslinking dipeptide; 3) matching the candidate crosslinking dipeptide obtained in the step 2) with the series-connected spectrogram in a fine manner, to obtain an identification result. The method does not need to use a special cross-linking agent, searching speed is fast, identification efficiency is high, and search sensitivity is high.